Zach - I think you are absolutely 100% right that prolonged exposure to cold will lead to a preferential storage of subcutaneous fat. Ever see a skinny walrus? However, I think that the cool fat thingy finds a loop-hole in that. It doesn't get into the chronic, prolonged cold exposure like so many people advocate (turn down thermostats, don't wear a coat, drink cold water all day long) he just recommends wearing it for a short duration while exercising to increase short-term calorie burn. Kind of a hack on CICO, if you will as it increases CO without much extra effort. I actually have one of these and wear it a couple times a month when I jog or do the treadmill, more in the summer. It adds about 5-6 pounds of weight and makes you tighten all your chest, arm, and ab muscles to fight the cold off. It's kind of a cool feeling (pun intended). I'm not going to jump up and down and say it got me ripped in 30 days or anything, but as a cool gimmick--it's pretty cool (pun intended once again). I also have some mini barbells I use, too. I don't think those make much difference, either, but it's fun to change things up.

I was really stoked though to see the calorimeter experiment in the video, I would never have guessed it ramped up the metabolism that much--I figured maybe like 10%--not 300%.

That is why people who live in very northern climates usually are not low bodyfat. Your body does adjust by adding in insulation.

People need to get away from the mindset that metabolism = cranking up calorie burn by any means nesseccary. It doesnt work like that and usually ends up with a negative outcome.

Otzi, i agree it was a cool video and his experiments are interesting. I just dont see the use in it. Cold exposure can be a good thing but inducing shivering for a long time does not seem realistic or at all pleasent.

"Pleasant" isn't always the ideal pursuit in life. What if you thought of cold exposure as exercise instead? When strength training, I do not consider the moment I am at the bottom of my squat to be "pleasant", but I do it because I gain the physiological benefits of lifting heavy things.

My own N=1 is the same, I am ~8%BF, and have been taking cold showers since 3/1/13. Recently, I've also started cold/ice baths as well. I have only gotten leaner. Muscle toning from shivering is pretty incredible. Its also great for relieving lower back pain from my desk jockey job.

Also, the science doesn't really work for your theory. I realize the numbers are never 100% accurate when talking about calories, but speaking in general terms, if you spend an hour/day in a cold situation that results in lets say an extra 300 cal burn, and do not consume an additional 300 cal then you are in a caloric deficit. This energy has to come from somewhere. If you repeat this every day, the deficit will continue, which wouldn't allow an opportunity for your body to "add insulation".

I do agree that the CFB is a gimic, but in the sense that its merely an expensive, fancy ice pack. I believe the cold exposure it generates, and increases in metabolic rate are real though.

For more information, check out Ray Cronise's work at Thermogenex - Fuel the Burn |. He purchased his own calorimeter and has been doing cold/water testing related to metabolism.

My experience with prolonged cold exposure was that it made me HONGRY. Led to overeating and some weight gain. Using the cold pack vest is no where near that intense, and is actually very refreshing. In the winter, my garage is usually about 40-45 degrees, perfect a run (or hill climb) on the treadmill. In the summer, it's usually 75-80 in there, so I wear the ice vest.

Really, the only thing 'gimmicky' is the name CoolFatBurner, but he had to call it something, right? If he'd have called it the Ice Pack Equipped Sleeveless Overgarment For Enhanced Calorie Burning, it may have been more truthful, but way less cool.